Jim Cramer believes there are important financial insights to glean from history. Currently he's says there's a lot to learn from the dotcom bubble.

In his ongoing examination of the era, the "Mad Money" host has found a common theme among some of the biggest losers; that includes Razorfish, Scient, Viant, PurchasePro.com and others.

Although some survived while others didn't, in these cases Cramer is more interested in similarities from the time of the IPO. Cramer says in each case, these companies came public without any real idea of how they were going to make money in the years ahead. "That's proven to be perilous."

And Cramer fears, again, there are companies coming public that may be in a similar situation.

Looking at what happened to the 2000-ear failures, Cramer said, in addition to the absence of a path to profits, "Those companies also had far too much competition, they carried high costs and they were competing with deep-pocketed rivals."

Cramer believes the companies outlined above are in those circumstances, too.

Unless, business dynamics change sharply, even after year to date declines of 30 - 50 percent or more, Cramer thinks the path of least resistance will remain lower.

Now there is some good news, here. Cramer does not think the concerns apply to the majority of companies that IPOd this year. That's a big difference from 2000.

Cramer says, stocks of software-as-a-service companies that have fallen as much or even more as their e-commerce counterparts aren't facing the same perils.

"Most of these cloud companies came public with a clear understanding of how they would make money. In these cases the stocks declined because they became incredibly expensive, trading at excessive multiples. But at the end of the day, the software as a service model is a legitimate business model and profits should triumph."

Therefore, Cramer doesn't believe current woes will have the same broad impact as they did 14 years ago.

"When I take a walk down memory lane and look at all the failed Internet consultancies of the dotcom period, they feel eerily similar to the current crop of companies that are designed to help other businesses advertise online. If 2000 is any lesson, these stocks, which have already been crushed, can go a lot lower."